Photooxidative Removal of p-Nitrophenol by UV/H2 O2 Process in a Spinning Disk Photoreactor: Influence of Operating Parameters

摘要： In this paper, spinning disk photoreactor (SDP) has been used for the removal of a refractory pollutant, namely p-nitrophenol (PNP), in UV/H2O2 process. The effect of various parameters such as the plate type in the SDP, concentration of oxidant (H2O2), fluid volume, initial concentration of PNP, distance of the lamps from the spinning disk, distance of the lamps from each other, pH, and rotation speed of the spinning disk in the removal efficiency has been investigated. The results indicated that the use of scrobiculate disc instead of flat disc significantly increased the removal percentage of PNP from 46 to 100 % for the irradiation time of 20 min; it also increased with increasing H2O2 concentration, but the increase in fluid volume and the initial concentration of PNP reduced the removal percentage of PNP in the SDP. The increase in the distance of UV lamps from each other and from disc surface in the SDP reduced the removal percentage of PNP. However, the increase in pH to 5.5 increased removal efficiency while increasing pH above 5.5 reduced PNP removal efficiency. The disk rotation speed from 0 to 90 rpm increased the removal percentage from 49 to 70 % for the irradiation time of 5 min, but increasing the rotation speed to more than 90 rpm reduced the removal efficiency.